604.03Construction Methods, General.Construct the specified
structures according to the plans.Place
inlets, catch basins, inspection
wells, junction chambers, monuments, or precast outlets
at the locations and elevations shown in the plans according to the standard
construction drawings or as directed by the Engineer.Place manhole castings at the elevation and
station with offset to the center of the casting or as directed by the
Engineer.Place the manhole base at the
elevation and station with offset to agree with the pipe station, offset and
pipe invert elevation according to the standard construction drawings or as
directed by the Engineer.Use flat slab
top manholes as shown on the standard construction drawing. Do not remove the
flat slab top manhole lifting devices.

If the Engineerchanges the structure elevation by more than 1
foot (0.3 m), the Department will pay according to 109.05.

Thoroughly mortar with a flush mortar joint the
underdrain outlet pipe to the precast reinforced concrete outlet.Furnish and place lateral sewer connections
including drops and leads except pipe included in Item 603.

Locate or cut conduits as shown on the standard
construction drawings so they do not protrude inside the structure walls.

Take adequate precautions to prevent structure
concrete or mortar cement from freezing.Preheat the brick, concrete block, or precast concrete structure
throughout the entire mass to a temperature between 50 to 80 °F (10
to 27 °C)
before placing mortar if the ambient temperature is 40 °F (4 °C) or
less.

Set iron frames, tops, and covers of the type
shown on the plans in a mortar bed with a flush mortar joint.

2.Remove the existing walls of manholes down to the
spring line or below as necessary.

3.Remove existing walls of catch basins and inlets below
the window openings, grates, or any points of wall failure.

4.Using the salvaged casting, reconstruct the structure
to the new grade, conforming as nearly as practicable to the existing dimension
and type of construction.

B.Adjustment to grade

1.Carefully remove and clean the existing frame, adjust
the height of supporting walls, and reset the existing frame in a bed of
concrete mortar or structure concrete to the new grade.

2.Carefully remove the existing cover or grate and
install a casting or an approved adjusting device on file at the Laboratory or
an adjusting device approved by the Engineerto the new grade and install per the
manufacturer’s recommendations.

604.04Excavationand Backfill.Excavate to dimensions that provide ample room for
construction.

The Engineerwill require the removal of unsuitable
material below the structure bedding.Replace unsuitable material with Item 603
StructuralBackfill.When the Engineer requires the removal and
replacement of unsuitable material below the bedding for precast structures and
below the structure for cast-in-place structures, the Department will provide
compensation according to the Contract or by Supplemental Agreement.

Ensure that the backfilling follows the completion
of the work as closely as the type of construction will permit.Do not disturb the structure while
backfilling.Backfillstructures located within the pavement area
with structural backfill to the subgrade according to Item
603, Type A or B conduit.Backfill
structures outside of the pavement area according to Item 603,
Type C conduit.

604.05Brickand Block Masonry.Thoroughly wet brick and
concrete block masonry units before laying in the mortar, and lay the brick and
masonry units with a flush mortar joint.

Take adequate precautions to prevent concrete and
mortar from freezing.Do not set brick
and masonry units having a temperature of 40 °F (4 °C) or
less with mortar until heated.When
required, heat to ensure that a temperature of 50 to 80 °F (10 to 27 °C) is
obtained throughout the entire mass of the material.

Cure
the exposed surfaces of all brick and block masonry by covering with wet burlap
for 48 hours or by applying curing membrane according to Item 511.

604.06Precast ConcreteModular Construction.Furnish precast bases on a
compacted structural backfill bed having a minimum thickness of 3 inches (75
mm).Ensure that the structural backfill
bed is level and uniformly support the entire area of the base.

After placing the pipe, grout all openings between
the pipe and structure less than 4 inches (100 mm) with mortar and grout all
openings between the pipe and structure greater than 4 inches (100 mm) with
nonshrink mortar.Seal all joints
between modules with materials specified in Item 603 for
Type A, B, C, D, or F conduit.

Cure median inlets with the same materials and
methods specified in 622.07.

The manufacturer of precast modular items must be
certified according to Supplement
1073.